| Abstrakt: |
In five different regions of the country 5460 subjects were examined as to the occurrence of neutralizing antibodies against the three types of poliomyelitis virus. Five different age groups were included in the study, viz. 3-4 years, 8 years, 13 years, and about 25 and 50 years. As a rule, in the regions with a low attack rate of paralytic poliomyelitis the incidence of antibodies at an early age was higher than in regions with a high attack rate. In areas where numerous paralytic cases occurred during the epidemic period in 1953, the incidence of antibodies against type 1 predominated over the two other types. This was true even of age classes which earlier had lived through years with a particularly high poliomyelitis incidence. The populations of the two largest cities of the country, Stockholm and Gothenburg, showed a remarkable difference as regards the seroimmune pattern against poliomyelitis. In Gothenburg a comparatively high incidence of antibodies was demonstrated at earlier ages than in Stockholm. This is in agreement with the facts that the total incidence of paralytic cases is low in Gothenburg, and that the proportion of paralytic cases occurring at earlier ages is higher in Gothenburg than in Stockholm. As a conceivable explanation of the early infections in Gothenburg it is pointed out that the water supply of this town is based on purification of river water heavily contaminated with faecal matter, whereas Stockholm is supplied with water from a lake considerably less contaminated. The results of the serologic examinations were further utilised for an approximative estimation of how the risk of a poliomyelitis infection being manifested by paralysis is increasing with rising age. [ABSTRACT FROM AUTHOR] |
